Projectile



Nov. 3, l953 v. s. BLACKER 2,657,630

PROJECTILE Filed Oct. 24, 1951 2 Sheets-Sheet l A Homey Nov. 3, 1953 L.v. s. BLACKER PROJECTILE 2 Sheets-Sheet 2 Filed Oct. 24, 1951 AttorneyPatented Nov. 3, 1953 UNITED STATES ATENT OFFICE PROJECTILE LathamValentine Stewart Blacker, Coldhayes, Liss, England 7 Claims.

This invention relates to that kind of projectile which is dischargedfrom a barrelled Weapon by an explosive charge and which has a tailjoined to the head by a tube. To ensure accuracy when such a projectileis red it is important that the gases produced by the explosive chargeshould be closely confined behind the projectile Within the barrel, andtherefore a gas check may advantageously be provided behind the tail tomake a gas seal with the barrel.

When there is a gas check the force of the explosion is transmitted fromthe tail to the head. A substantial load is therefore applied to thetube connecting the head and tail, and to take this load the tube mustbe heavy. This in turn shifts the centre of gravity further aft than isdesirable.

It is an object of the present invention to provide a projectile of thiskind with a gas check and means for transmitting thrust from the gascheck to the head independently of the tube connecting the head andtail.

It is another object to provide a projectile of this kind with acombined gas check and thrust transmitting assembly which is jettisonedin flight.

It is a further object to provide an explosive charge for propelling agas check forcibly rear- Wards and so assisting the flight of theprojectile.

It is yet another object so to construct a gas check assembly that whenpressure is applied to the gas check the assembly moves forwardsrelatively to the projectile and imparts a forward blow to its head.

Essentially a projectile embodying the inven tion has a gas checkbehindV the tail, a device constituting a strut Within the tube fortransmitting thrust from the gas check to the head, and an explosivecharge Within the tube for jettisoning the gas check and strut devicefrom the projectile in flight. The strut relieves the tube of the thrustduring discharge, and the jettisoning of the gas check and strut ensuresthat in flight the projectile will have low drag and a centre of gravityin a satisfactory position. The reaction of the explosion of thejettisoning charge assists the projectile in flight. The invention willbe most clearly understood by reference to the accompanying drawingswhich show three projectiles embodying the invention. In these drawings-Figure 1 is a longitudinal section of the rear part of a mortar bomb andcartridge;

Figure 2 is a longitudinal section of a bomb and cartridge forbreech-loading into a gun; and

Figure 3 is a longitudinal section of a further mortar bomb andcartridge.

The head 2 of the bomb shown in Figure 1 is of streamline form andcontains an explosive charge. It is steadied in flight by a drum tail 8connected to the head by a light tube I0.

Before firing, the bomb is fitted with a cartridge and gas checkassembly. This includes a primary charge I2 which fires the bomb from amortar and which is contained in a body HlY together with a primer I6.The gas check is constituted by a thin cup ZE! Which is expandedradially into Contact with the barrel when the bomb is red by the chargeI2 and which bear against a thick flange I8 on the body.

The front of the body I4 is formed as a spigot which makes a tight pushnt in the end of the tail tube ID and rests against a cover 22 onthe endof a thick Walled tubular strut 24. This strut constitutes a thrusttransmitting device,

and it houses a secondary charge 25 for jettisoning the entire cartridgeand gas check assembly and bears Iagainst the base of the head 2.

Initially the extreme diameter of the cup 20 is, like that of the head,slightly less than the internal diameter of the barrel of the mortarfrom Which it is fired. Thus the bomb with the cartridge and gas checkassembly Will pass freely down the barrel. When the primary charge I2 isred upon engagement of the primer I6 withv a fixed ring pin, the cup 29expands slightly and its trailing lip makes a seal with the barrel.

The thrust produced by the explosion of the primary charge istransmitted to the bomb through the ange I8, the body Ill, the cover 22and the strut 24. Thus no thrust is applied to the tail tube Iii, whichcan be made just strong enough to carry the tail.

The explosion of the primary charge also drives forward a small cup 32within the bodyy l. This cup vcarries a ring pin 3d which hits a primerin the cover 22 and so res the secondary charge 25. Pressure builds upWithin the tail tube I and forces a lip 2l on the cover 22 radiallyoutwards into sealing contact with the tail tube Iii. Shortly after thebomb is clear of the mortar this pressure overcomes the decliningpropellent thrust resulting from the explosion of the primary charge andblows the cover 22 out of the tail tube, so jettisoning the gas checkand also drawing with it the strut 24, which is held to the cover by aring 23. The proportions of the primary explosive charge by which theprojectile is discharged and the secondary charge within the tube aresuch that immediately after being jettisoned the gas check has avelocity towards the weapon. In this way a considerable momentum istransferred from the gas check to the projectile without any addition tothe recoil of the weapon, because the secondary jettisoning charge actsafter the pressure and recoil resulting from the explosion of theprimary charge have reached their `peak. The'drag of the gas checkwhenritlis travelling backwards is greater than when it is travellingforwards and so it does not return far along its path of discharge. Byreason of this drag it may be propelled rearwardly with substantialenergy without endangering the operator of the weapon,:andxfact therearward velocity of the gas check :may '.be greater than that withwhich .it leaves the barrel of the weapon. While the gas check "2Bremains with the bomb during its rst few feetV of ight, air passinginside the drum tail can escape througha slot 35. Thus thedragat thisstageis keptas low as possible.

The bomb shown inFigure 2 diiersffrom that shownin Figure linlittleexcept the proportions of 'itsparts The primary charge 38 isAhoused in :a `tube 4e which is surrounded by a cartridge case 42 andwhich is screwed yonto the bodyA of the gas check. This screwedconnection breaks on ring. r'I-he body i4 is elongated as a tubularspigot .46 which Vextends about half way up-the tail tube 48. It thusforms part of the strut, and the remaining tubular part -53 isshorter-than thestrut 24.in Figure 1. A delay 52ris incorporatedbetweenthe primerf and the secondary charge A56. This allows the bomb tomove about a foot `before .pressure begins to build up within theforwardvpartof the tube 4&8.

.In .the ,construction shown in .Figure 2 the thrust is transmittedthrough the spigot tube 46 to the=casing of the primer 54 and from thiscasing to .the strut .part 59 and thence to the head-0f the bomb.

In `the bomb Vshown in Figure 3 aspigot 58 extending from va gas checkv6E! `is initially located within a tail .tube 62 .by interengagement ofshallow. grooves 64 made in both the spigot 518 and the tube 62. :In`this ,position there V4is a space BEbetweenthe front of .the spigot andthe casing .66 of a `primer 68. When lthe primary charge 10 vis firedthe gas check is -driven forwards relatively vto Ythe projectile and thespigot 58 imparts a blow to the casing 5.8 `which -is-.transmitted to-the head 12 of the projectileby a strut composed of two conical parts'I4 and .16. At the completion of this forward movement there is still aclearance between the gas .check andthe end ofthe tail tube and .so noblow is imparted to .that tube.

This blow not only accelerates the projectile but also forces the part14 into they part 16 and the resultant expansion of the latter presses aange 18 on the casing 66 into contact with the bore of the tube 62. Asthe gas check is movingk -pon are assisted in fiight by the combustionof .an-additional rocket charge.

`I claim:

fl.. In a1pr'ojectile having a head, a tail and a'itube :connecting saidhead and tail the combination of Vagas .check behind said tail,'a strutwithin said tube adapted to transmit thrust from saidiga's check to saidhead, and means, including an explosive charge, within said tube forjettisoning said gas check and strut-from said projectile.

2. A combination as claimed` in claim l wherein aspigot rigid withsaidgas check enters said tubeand forms a part of saidstrut.

3. rA combination as claimed inc1aim2 wherein means are'providedforinitially locating-said spigot witha space between-the endthereofgandthe remainder of saidstrut.

4. In a projectile having a'head,a tail-and a tube connecting said headand tail .the .combination of a gas check behind said taiL-a strutwithink said tube adapted .to transrnitthrustfrom saidgas check to saidhead, and .means within saidtube for jettisoning said gas checkandstrutfrom said projectile, said .means .including aan explosive charge, aprimer, a movable Amember exposed to gas pressure vacting Von-saidfgascheck, and a firing ,pin carried by said movablemember and co-operatingwith said primer.

5. A combination vas .claimed in claim -1 and a primary explosive charge-or discharging Asaid projectile from a barrelled weapon, the.proportion between said primary explosive charge and said explosivecharge for jettisoning said lgas check being such that immediately afterbeing jettisoned said gas check Ahas a velocity towards said weapon.

I `6. A combination as claimed in claim 5 .wherein said proportion issuch that said velocityof said gas check towards said weapon is .greaterthan the Velocity of said projectile on leaving said weapon.

'7. A projectile having a head, a tail, a tube connecting said head andtail, a gas check behind sraid tail, strut means within lsaid tubeadapted to transmit thrust .from said gas check to said head, and anexplosive 'charge within saidltube adapted to jettison said gas checkandstrut means from the projectile in flight.

LATI-IAM VALENTINE. STEWART BLACKER.

No references cited.

